The goal of the proposed research is to further our understanding of the genetic basis of variation in life span in a model organism, the fruit fly Drosophila melanogaster. This will be done by fine-scale mapping of genes that control heritable variation in life span. Mapping will be confined to regions that span about 31% of the D. melanogaster genome. Those regions were found in earlier studies to contain important life span genes. An advanced intercross line (AIL) mapping design will be used to achieve a seven-fold increase in the precision of estimates of gene location, relative to the earlier studies. Microsatellites will be used as genetic markers for mapping, and composite interval mapping will be used to estimate gene locations and effects. The necessary microsatellites will be obtained by searching the on-line genomic sequence of D. melanogaster, which is available through the National Center for Biotechnology Information (NCBI). This project will lead to a better understanding of the genetic control of life span in a model organism. Identification of genes that are responsible for variation in life span will make it possible to evaluate the importance of competing theories for the evolution of aging and for the maintenance of genetic variation in life span, both significant unsolved problems. Identification of life span genes will also be important for evaluating molecular/physiological mechanisms of aging, such as theories based on oxidative damage. A better understanding of the genetics of life span in one complex animal is likely to inform similar research in other species, including humans. This project aims to shed light on the genetic basis of the aging process. [unreadable] [unreadable] This research may lead to understanding the mechanisms involved in age-related diseases in humans. [unreadable] [unreadable] [unreadable]